Heretofore, for controlling chemical liquid in a semiconductor manufacturing process and a liquid crystal manufacturing process, various fluid devices are used. The fluid devices include: valves such as flow rate control valves and open/close valves, filters, sensors such as pressure sensors and flow rate sensors, and piping blocks such as joint blocks and passage blocks. In recent years, for achieving size reduction, these fluid devices are directly coupled to each other into a single unit and their connection sections are sealed. Patent Literature 1 discloses one example of a seal structure for connection sections in which a seal member is placed between a first part and a second part.
FIG. 36 is a cross-sectional view of an integrated panel 1100 that applies a conventional seal structure for connection sections. The integrated panel 1100 is constituted of a valve 1102 fixed on a panel member 1101 by bolts 1116 and seal members 1112 are placed between the panel member 1101 and the valve 1102.
The panel member 1101 is made of fluorocarbon resin. On a connection section 1101a of the panel member 1101, a vertical passage 1104 communicating with a first port 1103 and a vertical ring passage 1106 formed around the vertical passage 1104, communicating with a second port 1105 are opening. The connection section 1101a is formed with groove-ridge sections having annular protrusions 1107 outside the passages 1104 and 1106. On the other hand, the valve 1102 includes a passage block 1108 made of fluorocarbon resin. On a connection section 1108a of the passage block 1108, a supply-side passage 1109 facing the vertical passage 1104 and a discharge-side passage 1110 facing the vertical ring passage 1106 of the panel member 1101 are opening. The connection section 1108a is formed with groove-ridge sections having annular protrusions 1111 outside the passages 1109 and 1110.
The seal member 1112 is made of ring-like shaped fluorocarbon resin and formed on both ends with annular grooves 1113 and 1114 fitted with the annular protrusions 1107 and 1111 respectively. Each groove width of the annular grooves 1113 and 1114 is designed 0.75 to 0.85 times narrower than a groove width of the annular protrusion so that inner and outer peripheral surfaces of the annular protrusions 1107 and 1111 are pressed to have contact with corresponding inner peripheral surfaces of the annular grooves 1113 and 1114. Further, the seal member 1112 is formed with a ring-shaped flange 1115 for attachment and detachment horizontally extending from an outer peripheral wall of the seal member 1112. A thickness of the flange 1115 is designed to be thinner than a clearance W between the connection section 1101a and the connection section 1108a. 
For attachment of the seal member 1112, the seal member 1112 is firstly mounted on the panel member 1101 in a manner that the annular protrusion 1107 of the panel member 1101 is inserted in the annular groove 1113 of the seal member 1112. After that, the valve 1102 is mounted on the panel member 1101 in a manner that the annular protrusion 1111 of the passage block 1108 is inserted in the annular groove 1114 of the seal member 1112. Subsequently, the bolts 1116 are fastened to fit the annular protrusions 1107 and 1111 in the annular grooves 1113 and 1114 of the seal member 1112.
For detachment of the seal member 1112, the bolts 1116 are unscrewed first and the valve 1102 is removed from the panel member 1101. At this time, the seal member 1112 remains attached to either one of the panel member 1101 or the passage block 1108. Accordingly, the flange 1115 is pulled by a tool or fingers to detach the seal member 1112 from either one groove-ridge section of the panel member 1101 or the passage block 1108.